Rudder cable - was The Little Wheel in Back

[BD5ER]

Asking a question and taking this thread off on a tangent:

Been thinking about using some Spectra for rudder cables. Other than the
obvious poor heat tolerance, which shouldn't be a factor in my case for rudder
cables, what other problems, ecpected or unexpected, might I encounter if I
were to experiment in this manner? Abrasion, stretch, creep, and attachment
methods have already been considered.

Anyone already using Spectra for control cables?

>>>>> Now I'm really curious. Saw some stainless steel cable at the tractor
>>>>> supply the other day for about $1 foot. 1/8" and looked to be about 9
>>>>> cords, each with 7 wires. Is there a difference between the steel cable
>
>>>>> found at the tractor supply and what AS&S ships?
>>>>
>>>>Biggest difference is probably the per-foot marking on the price tag.
>>>
>>>that is a dangerous complacency.
>>>aircraft wire has more wires in each "chord" to reduce the effects on
>>>cable strength of wear through the pulleys and guides.
>>>7 chords by 19 strands is the usual aircraft stuff.
>>
>>Actually, aviation cables come in a variety of layouts, depending upon the
>>usage of the cable. First number is the number of strands, second number
>>is the number of wires in each strand. You can multiply the numbers to
>>determine the number of individual wires in a given cable... so 1/8" 7x19
>>cable has 133 tiny wires, and 1/8" 1x19 has nineteen rather thick wires.
>>
>>Obviously, tiny wires are going to bend easier than thick wires. So the
>>7x19 cable is going to be more flexible than the 1x19. But it's going to
>>be more sensitive to friction; those little wires are going to wear through
>>faster than the thicker ones. But that stiff 1x19 is going to present more
>>problems when trying to form it around a thimble.
>>
>>Fly Babies use both types... 7x19 cables for the rudder, and 1x19 cables
>>for the bracing wires.
>>
>>Ron Wanttaja

[BD5ER]

>Yes. The Sparrowhawk ultralight sailplane.
>http://www.windward-performance.com/

Thanks for the info. Sometimes it's nice not to have to invent the wheel.
Guess I'll have to look into it.

[Ernest Christley]

Tim Ward wrote:
> "BD5ER" > wrote in message
> ...
>
>>Asking a question and taking this thread off on a tangent:
>>
>>Been thinking about using some Spectra for rudder cables. Other than the
>>obvious poor heat tolerance, which shouldn't be a factor in my case for
>
> rudder
>
>>cables, what other problems, ecpected or unexpected, might I encounter if
>
> I
>
>>were to experiment in this manner? Abrasion, stretch, creep, and
>
> attachment
>
>>methods have already been considered.
>>
>>Anyone already using Spectra for control cables?
>
>
> Yes. The Sparrowhawk ultralight sailplane.
> http://www.windward-performance.com/
>
> Tim Ward
>
>

What is Spectra, and what advantage does it have over steel cable?

--
----Because I can----
http://www.ernest.isa-geek.org/
------------------------

[Tim Ward]

"Ernest Christley" > wrote in message
. com...
> Tim Ward wrote:
> > "BD5ER" > wrote in message
> > ...
> >
> >>Asking a question and taking this thread off on a tangent:
> >>
> >>Been thinking about using some Spectra for rudder cables. Other than
the
> >>obvious poor heat tolerance, which shouldn't be a factor in my case for
> >
> > rudder
> >
> >>cables, what other problems, ecpected or unexpected, might I encounter
if
> >
> > I
> >
> >>were to experiment in this manner? Abrasion, stretch, creep, and
> >
> > attachment
> >
> >>methods have already been considered.
> >>
> >>Anyone already using Spectra for control cables?
> >
> >
> > Yes. The Sparrowhawk ultralight sailplane.
> > http://www.windward-performance.com/
> >
> > Tim Ward
> >
> >
>
> What is Spectra, and what advantage does it have over steel cable?
>
> --
> ----Because I can----
> http://www.ernest.isa-geek.org/
> ------------------------

It's ultra high molecular weight polyethylene (UHMWPE).
For a given diameter, it's stronger than steel, and much, much lighter.

Tim Ward

[Barnyard BOb --]

>> What is Spectra, and what advantage does it have over steel cable?
>>
>> --
>> ----Because I can----
>> http://www.ernest.isa-geek.org/
>> ------------------------
>
>It's ultra high molecular weight polyethylene (UHMWPE).
>For a given diameter, it's stronger than steel, and much, much lighter.
>
>Tim Ward
+++++++++++++++++++++++++++++++++++++

My first experience years ago with Spectra...
was with fishing line. Not cheap.

Genuine modern miracle space age stuff.



Barnyard BOb --

[BD5ER]

>Sounds like a solution to a non-existent problem.
>
>Rich "To save an ounce, lose a hamburger" S.


That weight reduction program is well underway. Hamburgers are in, just no
carbs.......and the weight savings is already many times greater than all of
the carbon and Spectra combined will save.

I agree there isn't much of a "problem" to be solved. Still, I like the idea
of something a bit different, otherwise I'd have just bought a 172.

[Dave]

BD5ER wrote:
>>Sounds like a solution to a non-existent problem.
>>
>>Rich "To save an ounce, lose a hamburger" S.
>
>
>
> That weight reduction program is well underway. Hamburgers are in, just no
> carbs.......and the weight savings is already many times greater than all of
> the carbon and Spectra combined will save.
>
> I agree there isn't much of a "problem" to be solved. Still, I like the idea
> of something a bit different, otherwise I'd have just bought a 172.
We use it in the skydiving industry for canopy lines. It appears to be
very strong and abrasion resistant. The lines aren't much different in
size than tooth picks. 500 or 800 pound test.
The only problem is, it shrinks when heated. The line sets on our
parachutes need to be replaced every so often because of abrasion heat.
Usually around 500 jumps or so.
Should not be a problem in most aircraft.
Also, UV can hurt the strength of the line.

Dave

[Rich S.]

"BD5ER" > wrote in message
...
>
> That weight reduction program is well underway. Hamburgers are in, just
no
> carbs.......and the weight savings is already many times greater than all
of
> the carbon and Spectra combined will save.
>
> I agree there isn't much of a "problem" to be solved. Still, I like the
idea
> of something a bit different, otherwise I'd have just bought a 172.

You need some of that stuff that was featured in "Fountains of Paradise" by
Arthur C. Clarke.

Rich S.

[Corrie]

"Rich S." > wrote in message >...
> "BD5ER" > wrote in message
> ...
> > I agree there isn't much of a "problem" to be solved. Still, I like the
> idea
> > of something a bit different, otherwise I'd have just bought a 172.
>
> You need some of that stuff that was featured in "Fountains of Paradise" by
> Arthur C. Clarke.

The space-elevator cable stuff? Welcome to the 21st century - it's
not quite unobtanium anymore. It's available (or soon will be) at
your local Nano Depot in the Buckytubes aisle. Carbon filaments made
of stacks of rings of carbon atoms. Tensile strength that makes steel
look like wet tissue. Now if you could only get it in lengths greater
than .01 mm ...

Corrie

[Rich S.]

"Corrie" > wrote in message
om...
>
> The space-elevator cable stuff? Welcome to the 21st century - it's
> not quite unobtanium anymore. It's available (or soon will be) at
> your local Nano Depot in the Buckytubes aisle. Carbon filaments made
> of stacks of rings of carbon atoms. Tensile strength that makes steel
> look like wet tissue. Now if you could only get it in lengths greater
> than .01 mm ...

Yeah - that's it. I'd like it at least 3-4" long for a cheese slicer.

Rich S.